Chronic rejection is the leading cause of death in heart transplant patients, yet, no effective treatment exists. One therapy that has shown promise is the use of HMG-CoA reductase inhibitors (statins), but the mechanism by which they operate remains unclear. This proposal describes a research project designed to delineate the role of HMG-CoA reductase pathway inhibitors in the prevention of chronic rejection in a murine cardiac transplant model. In addition, this project will lead to a greater understanding of the pathways affected in the formation of chronic rejection. This will be done by employing a novel model of chronic rejection which relies on bioluminescence imaging. The project has four specific aims: (1) the development and validation of the FVB Luciferase-GFP (beta-actin) to C57BL/6 cardiac transplant model of chronic rejection; (2) determination of the ability of atorvastatin to decrease the degree of chronic rejection in the model; (3) analysis of the ability of specific HMG-CoA reductase pathway inhibitors to suppress chronic rejection in this model; and (4) examination of the intracellular pathways affected by inhibition of the HMG- CoA reductase pathway using gene microarrays. [unreadable] [unreadable] [unreadable]